Deltaic Complexes of the Québec North Shore

• Main Authors: Dietrich, Pierre, Normandeau, Alexandre, Lajeunesse, Patrick, Ghienne, Jean-François, Schuster, Mathieu, Nutz, Alexis
• Other Authors: University of Johannesburg South Africa (UJ), Géosciences Rennes (GR), Université de Rennes (UR)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire des Sciences de l'Univers de Rennes (OSUR), Université de Rennes (UR)-Institut national des sciences de l'Univers (INSU - CNRS)-Université de Rennes 2 (UR2)-Centre National de la Recherche Scientifique (CNRS)-Institut National de Recherche pour l’Agriculture, l’Alimentation et l’Environnement (INRAE)-Institut national des sciences de l'Univers (INSU - CNRS)-Université de Rennes 2 (UR2)-Centre National de la Recherche Scientifique (CNRS)-Institut National de Recherche pour l’Agriculture, l’Alimentation et l’Environnement (INRAE)-Centre National de la Recherche Scientifique (CNRS), Geological Survey of Canada Québec (GSC Québec), Geological Survey of Canada - Office (GSC), Natural Resources Canada (NRCan)-Natural Resources Canada (NRCan), Université Laval Québec (ULaval), Institut de physique du globe de Strasbourg (IPGS), Université de Strasbourg (UNISTRA)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS), Centre européen de recherche et d'enseignement des géosciences de l'environnement (CEREGE), Institut de Recherche pour le Développement (IRD)-Aix Marseille Université (AMU)-Collège de France (CdF (institution))-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-Institut National de Recherche pour l’Agriculture, l’Alimentation et l’Environnement (INRAE), Aarhus University Aarhus, Olav Slaymaker & Norm Catto (Eds.)
• Format: Book Part
• Language: English
• Published: HAL CCSD 2020
• Subjects: Deltaic complexes; Laurentide Ice Sheet; Deglaciation; Ice-contact deposits; Glacifluvial deltas; Submarine fans; [SDU.STU.GM]Sciences of the Universe [physics]/Earth Sciences/Geomorphology; Canada; Ice Sheet
• Online Access: https://insu.hal.science/insu-02482620; https://doi.org/10.1007/978-3-030-35137-3_10

Print ISBN 978-3-030-35135-9Online ISBN 978-3-030-35137-3 International audience One of the most particular morphological features of the Québec North Shore (North Shore of the Estuary and Gulf of the St. Lawrence, eastern Canada) is the occurrence of deltaic complexes that form thick and extensive sediment bodies (gravel, sand and mud) along the modern coastline. The deltaic complexes were emplaced during the retreat of the Laurentide Ice Sheet from the region that commenced about 11 ka in the context of falling relative sea level. Deltaic complexes are made up of three distinct, superimposed depositional systems, consisting of: (1) ice-contact subaqueous fans and deltas, (2) ice-distal glacifluvial deltas, and (3) coastal suites and meandering channel belts. Ice-contact systems were emplaced immediately after deglaciation of the region at the front of the ice-margins. Subsequent ice retreat fed glacifluvial deltas in meltwater and glacigenic sediments until the complete retreat of the ice-margin from the drainage basin a few thousand years ago. The resulting shutdown in sediment supply led to the reworking of the now-inactive glacifluvial deltas by shore-related and fluvial processes that resulted in the deposition of coastal suites and meander channel belts. Submarine sediment accumulations and related morphologies revealed by high-resolution swath bathymetric and seismostratigraphic data collected off these deltaic complexes are the subaqueous counterparts of these deltas. The modern evolution of these deltaic complexes is controlled by the reworking, transport, and deposition of sediments by shore-related processes along the coast, on the shallow shelf, and through submarine channels and canyons.